#include <stdio.h>
#include <math.h>
#include <stdbool.h>

#define EP 0.00001

int main() {
    double x, y = 1.0, new_y;

    printf("Enter a positive number: ");
    scanf("%lf", &x);

    while (true) {
        new_y = (y + x / y) / 2;
        if (fabs(new_y - y) < EP * y) break;
        else y = new_y;
    }

    printf("Square root: %lf\n", y);

    return 0;
}
